Forty questions of importance to the policy and practice of native oyster reef restoration in Europe

Abstract

Oyster reefs are among the most threatened marine habitats globally. In Europe, oyster reefs have been extirpated from most locations within their historical range. Active restoration of the native oyster (Ostrea edulis) in Europe has grown substantially in recent years. In sharing experiences between oyster restoration projects in Europe at the Native Oyster Restoration Alliance conference, NORA2, in Edinburgh in May 2019, it became apparent that a number of similar barriers are experienced. This study identified the top 40 questions, which, if answered, would have the greatest influence on the policy and practice of oyster restoration in Europe. Initially 71 people were consulted across 28 institutions and 11 European countries to generate 194 questions. An established process of one round of pre‐workshop voting followed by a one‐day online workshop and two post‐workshop rounds of voting resulted in the final 40 questions. Questions were broadly grouped into the following 10 themes: baselines, site selection, restoration methods, quantifying benefits, disease management, biosecurity, genetic diversity and population differentiation, policy and management, novel technologies, and current and future threats. We anticipate that this list will provide a starting point for developing collaborative projects across the NORA network, as well as assisting policy makers and funders with identifying key areas that need to be addressed in order to overcome existing barriers to scaling up oyster restoration in Europe.

Sustainable large‐scale production of European flat oyster (Ostrea edulis) seed for ecological restoration and aquaculture: a review

“…Further challenges include the choice of adult broodstock oysters. The implementation of selection programmes focusing on strains tolerant to specific diseases and adapted to sitespecific environments on the one hand, and preserving a high genetic diversity of restored O. edulis populations on the other hand is of major importance (Pogoda et al 2020;zu Ermgassen et al 2020a).…”

Two parallel chromosome‐level reference genomes to support restoration and aquaculture of European flat oyster Ostrea edulis

“…aquaculture, bivalve, genomics, mollusc, restoration, shellfish restoration (Pogoda et al, 2019;Zu Ermgassen et al, 2020), and a revival in aquaculture production in Europe, as a complement to the Pacific oyster Crassostrea gigas. As such, it is expected that the timing of these genome releases will provide an extremely useful foundation for the purposes of comparative genomics (Regan et al, 2021), population genetics (Šegvić-Bubić et al, 2020), selective breeding (Gutierrez et al, 2018;Naciri-Graven et al, 1998;Peñaloza et al, 2022) and deep explorations into the biology of this species (see Colsoul et al, 2021 for review).…”

Global success in oyster reef restoration despite ongoing recovery debt

“…Given the biogenic reef building nature of oyster habitats, and a life history that leaves them vulnerable to allee effects, natural recovery is unlikely given the loss of structural habitat which is essential for oyster settlement. Therefore, intensive restoration efforts of oyster habitats have led to large capital investment in various methods, all aiming to increase the spatial area of oyster habitat, their functioning, and ecosystem services 17,18,19,20,21,22 .…”